Shed/Garden Supply

Hello All,

Just a quickie i hope. Tomorrow i will be implimenting the following and getting my mate (qualified spark) in to check everything, i would ask him but he's in a wedding all weekend and i don't wanna disturb him (probs won't get any sense out of him now anyway).

Supply->RCD->Henley Block->3Core 16mm SWA->Shed CU
Supply->RCD->Henley Block->House CU's (Old Electrics in House, Needs ReWire Later)

I have a TT supply (hense RCD b4 henley block). The run from the House to the Shed is approx 15m and is clipped to wall then ducted under patio (below 3 foot) into shed. House is fitted with Earth Rod outside.

Now for the question - Do i export the Earth from the house or install another earth rod close to shed?

Cheers In Advance
Jambo

I would install a new rod to make sure that you will have earth in both parts all the time. Otherwise loosing earth in the house will effect the whole installation.

You must protect the supply line to the shed with a fuse or contact breaker. The RCD will not do this.

The best way is to wire the shed supply to a breaker in the house CU.

Also I assume that the RCD you mention is a 100mA Time Delay RCD and the shed's CU will have a 30mA RCD in it?

RCD is 100mA but not sure if it is a TD one (don't think it is, says 100mA, 80A, CAT WEM 80/2), it is the only RCD in the installation atm. I plan on a full rewire and CU sometime in the next 6 months (electrics are really old, no earth in light circuit) where i will be using a overall 100mA TD RDC and 30mA RCD to protect the sockets & shower. No space in my (many) boards atm so is there anyway i can take the shed from the Henley block for now and when i replace the wireing and cu switching the shed to a 63A breaker on the 100mA TD RCD side and fitting a RCD in the shed CU. Pics below of current setup. Also do contactum do a modular 100mA TD RCD?






Another thing, i will be installing an earthing rod at the side of my shed for the shed CU, do i also need to connect the 3rd 16mm core from my swa to the earth terminals at both CU's as a backup?